GKN Aerospace is a world leading supplier of aerospace engine components, continuously
improving their design methods. One important area is the evaluation of
high cycle fatigue (HCF) at multiaxial stress states. A critical plane criterion has
been suggested to replace the currently used invariant criterion in order to improve
accuracy. However, experiments are required to support and verify the choice of
criterion.
Through a numerical comparison of criteria, states of stress where predictions differ
are identified. Among them, biaxial stress states with high mid stresses are of special
interest since such are often present in rotating engine components. Therefore, a
testing method able to generate this state of stress is desirable.
A literature review shows that the two most commonly used biaxial testing methods
are cruciform specimens loaded in two directions, and tubular specimens with
internal pressure. However, both methods require complex, expensive and rare laboratory
equipment. Hence, alternative methods are sought. Several concepts are
developed and their feasibility are evaluated through numerical simulations. Recommendations
regarding specimen geometry, test setup and failure detection are
given. Finally, advantages and concerns for the concepts are summarised.
The Disc bending-concept is considered to be most promising. It constitutes a
disc-shaped specimen, simply supported at its edges and transversely loaded in the
centre region. This set up creates a biaxial bending stress state, with a close to
uniform stress distribution. The concept may be thought of as a biaxial version of
the uniaxial four point bending technique.

BibTeX @mastersthesis{Olofsson2017,author={Olofsson, Niklas},title={Design of experiments for validation of multiaxial high cycle fatigue criteria},abstract={GKN Aerospace is a world leading supplier of aerospace engine components, continuously
improving their design methods. One important area is the evaluation of
high cycle fatigue (HCF) at multiaxial stress states. A critical plane criterion has
been suggested to replace the currently used invariant criterion in order to improve
accuracy. However, experiments are required to support and verify the choice of
criterion.
Through a numerical comparison of criteria, states of stress where predictions differ
are identified. Among them, biaxial stress states with high mid stresses are of special
interest since such are often present in rotating engine components. Therefore, a
testing method able to generate this state of stress is desirable.
A literature review shows that the two most commonly used biaxial testing methods
are cruciform specimens loaded in two directions, and tubular specimens with
internal pressure. However, both methods require complex, expensive and rare laboratory
equipment. Hence, alternative methods are sought. Several concepts are
developed and their feasibility are evaluated through numerical simulations. Recommendations
regarding specimen geometry, test setup and failure detection are
given. Finally, advantages and concerns for the concepts are summarised.
The Disc bending-concept is considered to be most promising. It constitutes a
disc-shaped specimen, simply supported at its edges and transversely loaded in the
centre region. This set up creates a biaxial bending stress state, with a close to
uniform stress distribution. The concept may be thought of as a biaxial version of
the uniaxial four point bending technique.
},publisher={Institutionen för tillämpad mekanik, Dynamik, Chalmers tekniska högskola},place={Göteborg},year={2017},series={Diploma work - Department of Applied Mechanics, Chalmers University of Technology, Göteborg, Sweden, no: 2017:04},}

RefWorks RT GenericSR ElectronicID 248087A1 Olofsson, NiklasT1 Design of experiments for validation of multiaxial high cycle fatigue criteriaYR 2017AB GKN Aerospace is a world leading supplier of aerospace engine components, continuously
improving their design methods. One important area is the evaluation of
high cycle fatigue (HCF) at multiaxial stress states. A critical plane criterion has
been suggested to replace the currently used invariant criterion in order to improve
accuracy. However, experiments are required to support and verify the choice of
criterion.
Through a numerical comparison of criteria, states of stress where predictions differ
are identified. Among them, biaxial stress states with high mid stresses are of special
interest since such are often present in rotating engine components. Therefore, a
testing method able to generate this state of stress is desirable.
A literature review shows that the two most commonly used biaxial testing methods
are cruciform specimens loaded in two directions, and tubular specimens with
internal pressure. However, both methods require complex, expensive and rare laboratory
equipment. Hence, alternative methods are sought. Several concepts are
developed and their feasibility are evaluated through numerical simulations. Recommendations
regarding specimen geometry, test setup and failure detection are
given. Finally, advantages and concerns for the concepts are summarised.
The Disc bending-concept is considered to be most promising. It constitutes a
disc-shaped specimen, simply supported at its edges and transversely loaded in the
centre region. This set up creates a biaxial bending stress state, with a close to
uniform stress distribution. The concept may be thought of as a biaxial version of
the uniaxial four point bending technique.
PB Institutionen för tillämpad mekanik, Dynamik, Chalmers tekniska högskola,T3 Diploma work - Department of Applied Mechanics, Chalmers University of Technology, Göteborg, Sweden, no: 2017:04LA engLK http://publications.lib.chalmers.se/records/fulltext/248087/248087.pdfOL 30